In Jill Lepore’s The Secret History of Wonder Woman, the noted author of many crucial books (including Book of Ages: The Life and Opinions of Jane Franklin), Harvard professor, and New Yorker staff writer turns her eye to some secret identities that we never knew about: the cultural history and personal arcana that led to Wonder Woman, the best super heroine in comics.

“Suffering Sappho!” “Great Hera!” Wonder Woman, an Amazonian princess from an island of women, clad in a gold tiara, gold bracelets, and knee-high red leather boots, crashed on American soil in her invisible plane in 1941, where she disguised herself as a secretary named Diana Prince and worked for the U.S. Military service. She was the creation of William Moulton Marston, a psychology professor and lawyer who invented the lie detector.

In The Secret History of Wonder Woman, Lepore points to how the women in Marston’s unconventional life shaped the values and ideals found throughout his comics: his wife, Elizabeth Holloway Marston; his (scandal!) long-term live-in mistress and the mother of several of his children, Olive Byrne; and Byrne’s aunt Margaret Sanger, the pioneering feminist and founder of Planned Parenthood, who worked to make birth control affordable and available for women.

So a man who lived a scandalous, unconventional life created an unconventional superhero, a strong female character whose encounters were a metaphor for the suffragette struggle and where feminism was going in the early 20th century. Lepore does a wonderful job of showing how Marston’s life and passions manifested themselves in Wonder Woman’s content.

Feminist utopian literature of the early 1900s, like Charlotte Gilman Perkins’ Herland (a deep cut from the author of The Yellow Wallpaper), shaped Marston’s vision of Wonder Woman’s island of Amazons. Sanger’s Woman and the New Race was a precursor to the philosophy of Wonder Woman: liberation comes from the female spirit running free, from love ruling over all, overcoming force and chains — and that meant empowering women to choose motherhood voluntarily (with birth control access).

Marston held many jobs throughout his life, and during one epoch, he was a professor at Tufts University. It’s where he met Byrne — she was his student, with whom he conducted a series of research experiments. One included going to a sorority party together, a “Baby Party,” where the Freshmen pledges were bound and tied, forced to do tasks, and then hit with sticks. This imagery would make it into the pages of Wonder Woman with the headline: “Etta Candy sentences Freshmen for their sins during ‘Baby Wee’ at Holliday College.”

Lepore is spry and able as she draws parallels between the comics and the lives of Marston and his “wives.” Wonder Woman was a wild success upon her debut, outselling other comics. It’s never been out of print. And once Marston died, Holloway and Byrne — who would live together for the rest of their lives — were cut out of the Wonder Woman story, even though Holloway demanded to be hired as an editor, and she sent in specific editorial guidelines. But Wonder Woman was lost to the Marston family.

Wonder Woman is a fascinating, wonderfully researched book, and Lepore sheds light on what had been a longtime secret for those in the know. Sanger denied her influence on Wonder Woman; and the bohemian set-up between Holloway, Byrne, and Marston was, essentially, the hidden identity behind the psychological forces that created Wonder Woman. There’s a part of reading this book that’s frustrating — clearly Lepore had wonderful access to the Marston family, but she’s coy about what went on between the three. We’re only allowed to infer. But going into the book, Wonder Woman was just a comic; where Lepore succeeds is when we close the book, with our visions of Wonder Woman changed completely. A true American weirdo, she’s a symbol laden with heady philosophies and ideas: bohemians, feminism, sex radicalism, suffrage, free love, androgyny, and the scariest idea of all — what would happen to the world if women were truly liberated?